Let me give detailed answer and solve your query as well.

The average time spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference which shows that smartphones and social media could be partly responsible for the changed behavior of teenagers now a days.

A.spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference which shows

This is a strong contender, in Non GMAT world it is 100% correct, but GMAT has it's own rules.

Why A is incorrect?

1. "Which" is used here without comma. In GMAT to refer preceded noun by which there must be a comma before "Which"

2. "a difference" after comma is appositive modifier, difference is an abstract noun, it is describing phenomenon mentioned in preceded clause. Use of which to refer "a difference" makes sentence wordy and redundant, however, according to me if which is replaced by that and we do not have option E then it is absolutely correct.

3. If you notice there is one difference between A & E. Active voice vs Passive voice, and if you have gone through OG explanations, there is a word "Rhetoric". Here active voice seems to be rhetorical compared to passive voice.

B.a 15-year-old spends online per day had jumped from 105 minutes to 146 minutes between 2012 to 2015 and showed

We use Past perfect tense only when it is absolutely necessary i.e when sequence of events matters, however, here it is illogical because had jumped and showed... conveys the wrong meaning. Ask this question after reading this answer choice, Who showed?

Parallelism not required here as it is not a list of actions jumped and showed. Wrong! Illogical

C.a 15-year-old spends online per day jumped from 105 minutes up to 146 minutes between 2012 to 2015, showing

Verb+ing modifiers after comma describes the subject of preceding clause. Subject of preceding clause is "a 15-year-old". Does "a 15-year-old" shows that smartphones and social media could be partly responsible for the changed behavior of teenagers now a days. NO! Wrong meaning.


D.between 2012 to 2015, spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes, a difference which showed

Similar to A. Wrong.


E.a 15-year-old spends online per day jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference showing

Correct!

rsrighosh

a 15-year-old spends online per day jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference showing

Spends is verb modifier, which modifies/describe time. Ask which type of time? the time, which a 15-year-old spends online.

jumped is the main verb of the sentence here.

Additionally

"a difference" describes phenomenon mentioned in preceding clause. Abstract noun/Appositive/Noun modifier construction.
"showing" modifies "a difference".

Take aways:

1. Abstract noun/ Appositive modifiers are always preferable in GMAT. But don't fall in love with them, pay more attention to prove them wrong or right.
2."Which" must be used after comma in GMAT to refer preceding noun.
3. Verb+ing modifers after comma always modifiy preceding clause i.e subject/action of preceding clause.
4. Active voice vs Passive voice construction.
5. Correct answer must conveys an intended meaning.

Please reply/quote in case of doubts. Let's discuss and learn.

The average time spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference which shows that smartphones and social media could be partly responsible for the changed behavior of teenagers now a days.

A.spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference which shows CORRECT
B.a 15-year-old spends online per day had jumped from 105 minutes to 146 minutes between 2012 to 2015 and showed no need to make them ||
C.a 15-year-old spends online per day jumped from 105 minutes up to 146 minutes between 2012 to 2015, showing
D.between 2012 to 2015, spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes, a difference which showed Wrong Construction
E.a 15-year-old spends online per day jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference showing

(A) I don't find any problem with this answer choice. It is clear and conveys the meaning perfectly. I will keep it for the moment.
(B) I don't understand the use of the past perfect here. Furthermore, making it parallel it does not make sense: The average time had jumped and showed?? No. The difference between the average time in 2012 and in 2015 showed bla bla bla.
(C) In a weird way has the same problem as (B). "Showing" is modifying the preceded clause and it has to make sense with the subject of the preceded clause: The average time. And again, the average time does not show bla bla bla
(D) The construction is a bit weird in this choice. "Spent online per day...." should modify " the average time". In some weird way, now is saying that the difference between the years 2012 and 2015 shows....
(E) I don't see anything wrong here. The only thing i can think of(but i'm not sure it is a problem with that someone please correct me!!! ): In choice (A) "spent online per day...." modifies "The average time". Ok. In choice (E) is introducing a new clause "a 15-year-old spends online per day". I will have putted "that" before this new clause: The average time THAT a 15-year-old bla bla.

IMO (A) is the answer, but i'm not very sure of my judgement from choice (E).
_________________

A.spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference which shows - Comma before which. Shouldn't be Past Tense Spent
B.a 15-year-old spends online per day had jumped from 105 minutes to 146 minutes between 2012 to 2015 and showed - Had Jumped Not required, 'and' is also not required.
C.a 15-year-old spends online per day jumped from 105 minutes up to 146 minutes between 2012 to 2015, showing - up to 146 minutes
D.between 2012 to 2015, spent online per day by a 15-year-old jumped from 105 minutes to 146 minutes, a difference which showed - Comma required before which. Awkward construction
E.a 15-year-old spends online per day jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference showing - Correct

Hi,
Could you please let me know why you have marked the word Spends in option E as red.
Its a verb for 15 yr old and is perfectly fine

Abhi077, GMATNinja, GMATNinjaTwo, generis, hazelnut

Experts, could you please provide a full explanation of this SC?

I am not sure about why choice A is incorrect. Furhtermore, I believe that the grammatical construction in B, C and E is wrong as the subordinator that is missing.

I think the right construction would be:

"The average time that a 15 year old..."

Similarly, the following sentence is incorrect:

The teacher is confident her students mastered the lesson --> as the subordinator that is missing.

Help on this SC would be very much appreciated.

Thanks

E.a 15-year-old spends online per day jumped from 105 minutes to 146 minutes between 2012 to 2015, a difference showing

As per my understanding the above option has two verb in the same clause ..... That is the reason I chose option A.

Can anybody please explain why E is correct?
_________________

Through out this thread I see people explaining that which without the comma doesn't modify 'a difference.' If it isn't modifying 'a difference' what is 'which' modifying in option A?
Perhaps this is just a rule I need to remember that in this scenario we need to modify 'a difference' and which without the comma isn't accomplishing that, so those answer choices (A and D) aren't correct.

VeritasKarishma, MentorTutoring

I chose E here as in A it seems to say that we are talking about a particular 15 yr old while we actually mean 15 yr olds in general

Is there any other error? Also the modifier in A ( a difference which shows....) is correct, right?

Thanks in advance!

Hello, GDT. I do not think this question would make it onto the GMAT™. The British English usage of the restrictive which does NOT come up in SC questions as a legitimate split (although it may appear in other Verbal questions or passages). Also, nowadays is a single word, not three. At any rate, the only real case that can be made for (E) is its adoption of the active voice over the passive voice in (A). The modifier is fine. Where else is it supposed to go, or, alternatively, where else is the time tag between 2012 to 2015 supposed to go? I would take from this question what I could and then shift my focus back to official questions.

Thank you, even so, for calling my attention to this one. It is always fun to lay eyes on a new question.

- Andrew

i thought you could only have "between X & Y", not "between X to Y"

Hello, AnirudhaS. As all the answer choices incorporate the same element in question, I did not think to touch on it, but I love delving into language, and you pose a fair question. I would very much prefer for the answers to read either from 2012 to 2015 (even though that might awkwardly introduce double froms) or between 2012 and 2015. However, it may be premature to create an absolute rule about the usage of between X to Y. You may find this thread from Using English to be of interest. I would expect GMAC™ to take a more traditional stance than a linguist, who might view the language as a constantly evolving organism, so if this split came up on the exam, I would be sure to play it safe and opt for between X and Y.

Thank you for thinking to ask.

- Andrew

All the answer choices are wrong!

You never say between X to Y.
The correct usage is - Between X and Y.

If we use Between X and Y in option A and E, both will be correct as they both are of the form noun+noun modifiers.

GMATNinja
What are your views?